Was wondering if anyone could give me some hints about the default settings on my new LaValentina Automatic. I have read many of the posts concerning technique for creating good shots using HX machines and have mainly been using my new Valentina as a semi-auto. Specifically, I was wondering about pre-infusion. I have experimented thoroughly with the various buttons, but as most of you know, the translated instructions for the Valentina are extremely lacking. After experimenting, each button seems to deliver various amounts of water. The first button seems to be just enough to pre-infuse and I have been using it as such. Then, I go ahead and pull a shot using the semi-automatic button. Is this correct form? If not, what should I do? Any insight woulld be appreciated.

bubba_p wrote:After experimenting, each button seems to deliver various amounts of water.

The Buyer's Guide to La Valentina covers the semi-automatic model. The only practical difference between it and yours is the volumetric dosing, which is used for ending an extraction after a fixed volume of water has been dispensed. This feature comes in handy in cafes or busy households when the barista suffers a moment of inattention, but most baristas watch the extraction and end it when blonding begins. You may find it useful to program one dosing key to the flush amount from idle and another to slightly more than that needed for a double espresso under the assumption you'll cut it off manually.

In the guide, I refer to the preinfusion of your model (and the semi-auto like mine) as progressive preinfusion because it relies on the gicleur (orifice) and vibe pump for slower pressure ramp up as compared to a "true" E61:

bubba_p wrote:The first button seems to be just enough to pre-infuse and I have been using it as such. Then, I go ahead and pull a shot using the semi-automatic button. Is this correct form?

I refer to the technique of running the pump for a moment, pausing, then starting again as "pre-wetting" the puck, not preinfusion, because the group depressurizes completely. That's not the purpose of the volumetric dosing. I tried it and found pre-wetting the puck beyond a couple seconds muddied the espresso's taste.